Intraplate earthquakes in North China - Intraplate Earthquakes - page 109

XI around the epicenter. Within the 44 km long and 18 km wide epicentral region all
buildings were wiped out.
Earthquake damage was reported in 45 counties of three provinces. The death toll varies
among different records, ranging from

470,000 (Yao et al ., 1984 ; Min et al .,
1995 ) . Damage was widespread and extended to more than 250 km from the epicentral
region. More than 100,000 houses and public buildings (mainly temples) were destroyed;
fissures and sand blows were recorded in many places.
Since the 1960s, the site(s) of the Hongdong earthquake and the historic records have
been studied by various groups (Su et al ., 2003 ) . The 60 km long Huoshan fault was
identified as the hosting fault (Xu and Deng, 1990 ) . Xu and Deng ( 1990 ) estimated the
surface rupture of the earthquake to be 45 km long with dextral and normal slips. They
concluded that themaximum strike-slip displacement was about 10m; themaximumnormal
slip was about 3-5 m.

270,000 to

1556 Huaxian earthquake (M 8.3)
The M 8.3 Huaxian earthquake occurred in the middle of the night of January 23, 1556,
within theWeihe rift. The annals of theMingDynasty describe it this way: “Shanxi, Shannxi,
and Henan provinces shook simultaneously with thundering sound. Damage was especially
severe in Weinan, Huaxian, Zhouyi, Shanyuan, and Puzhou counties. Ground cracked,
water gushed out, houses sank into ground, and hills were created suddenly. Rivers flooded,
mountains collapsed, the death toll with named victims reached over 830,000; unnamed
victims were countless.” Landslide, flooding, famine, the bitter weather, and plague all
contributed to the stunning death toll. This is the deadliest earthquake in human history.
Damage was reported in 101 counties in Shanxi province and four neighboring provinces,
over a region of

280,000 km 2 . The maximum intensity reached XI in the epicentral
region of 2,700 km 2 . Historic records include detailed descriptions of surface ruptures,
liquefactions, terrain changes, and flooding of the Yellow River and the Weihe River (Li,
1981 ) .
The rupture was on the transtensional Huashan fault; the ruptured surface trace was
about 200 km (Huan et al ., 2003 ) . The average displacement was about 4 m (Xu and Deng,
1996 ) . Within the epicentral region, broad subsidence occurred north of the fault and uplift
south of the fault. The vertical offset reaches 10 m in Huaxian County.

1668 Tancheng earthquake (M 8.5)
The M 8.5 Tancheng earthquake occurred in the evening of July 25, 1668, on the Tanlu
fault near Tancheng County (34.8

E), Shandong Province. More than 50,000
people were killed, and damage was reported in 150 counties (Ma and Zhong, 2009 ) .
This earthquake was recorded in more than 500 historic topics and monuments. The
annals of the Tancheng County described the earthquake as follows: “In the evening,
a piercing sound suddenly came from the northwestern direction. The houses and trees
moved up and down twice or three times, and then shook from side to side. The city walls,

° N, 118.5 °